1. Field of the Invention
The present invention relates to a computing device using Bluetooth. More particularly, the present invention relates to an apparatus and method for obtaining information on Bluetooth devices in a computing device using Bluetooth.
2. Description of the Related Art
Bluetooth, a technology for performing local wireless communication, realizes communication between devices existing in a short range using an Industrial Scientific Medical (ISM) band of 2.4 GHz. For example, a portable terminal can enable various services such as a wireless headset, printing, file transmission, etc. using the Bluetooth technology.
To establish a connection using Bluetooth, a process of searching for another party device in a first device is performed. This is called an inquiry process. That is, the first device, operating as a master, has to perform the inquiry process. The inquiry process is subdivided into an inquiry for obtaining a Bluetooth Device ADDRess (BDADDR) of the other party device and a name request (name_req) inquiry for obtaining a name of the other party device.
Upon beginning the inquiry process, a master device does not have information on devices operable as slaves. In other words, the master device cannot be aware if any slave device waits to receive any frequency channel. Thus, the master device repeatedly transmits an inquiry packet, which is a type of beacon, in every slot. The inquiry packet transmission includes changing a channel within 32 frequency channels set for an inquiry purpose. Thus, the slave device selects one of the 32 frequency channels and identifies reception or non-reception of the inquiry packet during a specific duration of time. If the inquiry packet is not received during the duration of time, the slave device changes a channel and then, again identifies the reception or non-reception of the inquiry packet. As a result of repeated attempts, if a transmission frequency channel of the master device is matched at random with a reception frequency channel of the slave device, the slave device receives the inquiry packet.
As described above, in order for an inquiry packet of a master device to be received by a slave device, an attempt to transmit/receive the inquiry packet has to be repeatedly carried out until the transmission frequency channel is matched with a reception frequency channel. That is, to ensure successful reception of the inquiry packet, a constant period of time has to be guaranteed. Accordingly, there is a problem that time taken to search for slave devices becomes very long. Further, if a search time is limited, there is a problem that, though a plurality of slave devices exists around a master device, only some of the slave devices are searched for because of the limited amount of search time.